title: Biosynthetic origin of alchivemycin A, a new polyketide from Streptomyces and absolute configuration of alchivemycin B.
abstract: Biosynthetic origin of 2H-tetrahydro-4,6-dioxo-1,2-oxazine, an unprecedented structural unit first discovered in alchivemycin A (1), was investigated by feeding (13)C-labeled precursors. Incorporations of both [1-(13)C]glycine and [1-(13)C]-N-hydroxyglycine into the carbon at the 4-position of this six-membered ring indicate that the hydrooxazine ring is assembled through a PKS-NRPS hybrid pathway. Additionally, alchivemycin B (2), a deoxygenated analog of 1, was isolated and its relative and absolute configurations were determined by spectroscopic analysis including NMR and CD and X-ray crystallography.
authors.affiliation: Biotechnology Research Center, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan.
authors.forename: Youngju
authors.initials: Y
authors.lastname: Kim
authors.forename: Yasuko
authors.initials: Y
authors.lastname: In
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Ishida
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Onaka
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Igarashi
mesh_terms: D018360:Crystallography, X-Ray; D018942:Macrolides / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013302:Streptomyces / Q000737:chemistry*
chemical_list: D018942:Macrolides; C553074:alchivemycin A; C585985:alchivemycin B